Freedom of choice still needs to have its limits. We all have certain responsibilities that may impose upon our right to make our own decisions, but we are often obliged to fulfil those responsibilities.
To throw out an extreme example, by law parents are not allowed to choose not to look after their children as long as they are minors. They have certain responsibilities that they cannot choose to neglect as long as they have children in their custody. Even in a society that allows freedom of choice, they are not allowed to choose to be neglectful of their children.
More appropriate to this scenario, if your employer asks you to perform a task that is within your job description you cannot choose not to do it simply because you don't feel like it. Well, you can, but you won't be employed for very long.
Even though I can sympathise with GP's frustration and desire not to talk to the media, we all have commitments, obligations and responsibilities to fulfil. Perhaps the NBA could be fairer by offering a compromise when it comes to a team and players making themselves available to the media. But like I said before, even though the current system is a little unfair/demanding of players and coaches, if they were free to choose not to speak to the media, most of them probably never would.